Implementing QTreeView in QComboBox using Qt- Part 2

Comments

Article Provides a default model/view implementation of a tree view. It’s a good thing when we want to create an application which contain of all data storage view. In many application like file manager, Bluetooth file transfer this view is needed. Article named with “Implementing QTreeView_in_QComboBox-I” is also the 70% same thing. Its an advance look of that article.

[--fasttrack 18:13, 16 September 2009 (UTC)]

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Article Metadata

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Tested with

Devices(s): S60 Emulator

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Compatibility

Platform(s): Qt

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Article

Keywords: QComboBox,QTreeView,QDirModel

Created: mind_freak (31 Jul 2009)

Last edited: hamishwillee (11 Oct 2012)

Introduction

This code demonstrates the QTreeView implemented in QComboBox. Here you can expand the tree view and also select the file you want, no restriction of QComboBox closing on one click, you can select items upto any level.

Name of classed used:

QTreeView-Provides a default model/view implementation of a tree view.

QDirModel-Provides a data model for the local file system.

Source Code

#include <QtGui/QApplication>
#include "widget.h"
#include<QComboBox>
#include<QDirModel>
#include<QTreeView>
#include<QEvent>
#include<QMouseEvent>
#include<QModelIndex>
#include<QDir>
class TreeBox : public QComboBox
{
public:
        TreeBox(QWidget* parent = 0) : QComboBox(parent), skipNextHide(false) //Widget creation
        {
                setView(new QTreeView(this));
                view()->viewport()->installEventFilter(this);
                QComboBox::resize(200,30);
        }
 
        bool eventFilter(QObject* object, QEvent* event)
        {
                if (event->type() == QEvent::MouseButtonPress && object == view()->viewport())
                {
                        QMouseEvent* mouseEvent = static_cast<QMouseEvent*>(event); 
                        QModelIndex index = view()->indexAt(mouseEvent->pos());
                        if (!view()->visualRect(index).contains(mouseEvent->pos()))
                                skipNextHide = true;
                }
                return false;
        }
 
        virtual void showPopup()
        {
                setRootModelIndex(static_cast<QDirModel*>(model())->index(QDir::rootPath()));
                QComboBox::showPopup();
        }
 
        virtual void hidePopup()
        {
                setRootModelIndex(view()->currentIndex().parent());
                setCurrentIndex(view()->currentIndex().row());
                if (skipNextHide)
                        skipNextHide = false;
                else
                        QComboBox::hidePopup();
        }
 
private:
        bool skipNextHide;
};
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
        TreeBox combo; //Class object declaration
        QDirModel model;
        combo.setModel(&model); //implemention QDir model
        combo.show();
    return a.exec();
}

Screenshot

Related Links

Implementing QTreeView in QComboBox using Qt- Part 1